Study On Investigation And Evaluation Of Hilly Red Resources In Zhejiang Province

Zhejiang is one of the provinces with the lowest amount of land resources in China. According to the data of 2004, The per capita area of land resources in Zhejiang province was 0.23 hectares only, just making up 9.81% of the world average and 29.6% of the country average. Among these, the per capita area of cultivated land resources in Zhejiang province was 0.045 hectares only, less than the half of the country average. With the development of economy and urbanization, the contradiction of land use between supply and demand is increasing, and it becomes the main limiting factor which restricted economy and urban development. Therefore, besides exploiting the coastal tideland to keep dynamic balance of total amount of cultivated land and insure the grain security, it is necessary to make good use of hilly red soil resources. Through orderly exploitation and utility of hilly red soil resources, it maybe can resolve the contradiction of land use between supply and demand, and realize sustainable development of agriculture and national economy in Zhejiang province.Observing the research present situation of soil resources evaluation and land use plan in both and abroad, analytical method, theory and research means of soil resources evaluation had been studied thoroughly, some achievements were gained and they were put into use in practice extensively. But in some extent, there are still some shortages: In many cases, previous evaluations and plans used land type as evaluation basic unit, the result of plan is difficult to put in to use;Previous evaluations and plans were always carried out by scientists engaged in land science and agricultural science in long term, who made it by investigating on-the-spot, then combining it with experience. These conventional methods have many shortages, for example, a great amount of investigation work, much difficult to reach a common criterion, much poor precision to fix space position etc. Computers used in this field were only as supplementary implements that could not make data renewed and evaluation systematized. However, GIS methods used in this paper are very helpful to integrate the site investigation and data base management, the use of land evaluation and space analysis methods, the policy of territory distribution and applying model, increasing the capacity of space analysis and data renewal, improving the level of territorial space policy, especially for the study of multi-objective and multi-factor land use policy, GIS has extensively potential advantages.The main conclusions of this study are summed up as follow:1. considering the definition of hilly area in both China and abroad, the condition of Zhejiang province and the result of agriculture regional planning, in this paper, the definition of hilly area which depends on the condition of water/temperature and view of soil genesis was described as "range from foot of hill to the upper limit which is 250 meters high in north region, 300 meters high in east and center region and 350 meters high in south region. According to The Law of Soil and Water Conservation (in China), it gets rid of the area whose slope greater than 25 degrees. Ultimately, the area of hilly red soil resources in Zhejiang province was about 2488809.26 hectares.2. Through using nine images of ETM+ (multi-spectrum bands, spatial resolution of 30mx30m,panoramic bands of 15mx 15m), we finished the land use information investigated by visual interpretation. Basing on it, we can overlay the data including the terrain data, the soil data, the district data and the land use data by extensions of spatial analysis and analysis tools in Arc/Info. Finally, we set up the database of hilly red soil resources, its attributes included elevation, slope, aspect, land use, soil type and district and so on.3. By overlaying maps, adapting the integrated drawing units as the evaluation basic units, using APH-Fuzzy integrated evaluation and BP neural network respectively evaluated the exploited potential of hilly red soil resources. Then according to the terrain maps, soil maps and land use maps, compare the results of two methods, examining if the results coordinate with the reality, the results showed that it is tally with the actual situation. These results make it possible to put the land use plan in to practice and bring forward the assumption of agriculture regional planning, meanwhile, it is possible to achieve the moving evaluation of multi-objective hilly red soil resources by renewing the data, transforming the objective and the index of evaluation by the database of hilly red soil resources.4. Set up the database inquiring system of the hilly red soil resources by VB and AO. This system overcomes the disadvantage that other former systems have numerous functions and unfriendly user's interfaces, make it convenient to operate.